My cat Odie is about 18. She seems to have a problem every five to seven days going poop. She comes out of the litter box howling and then she throws up and poops on the bed. The stool doesn’t look hard and her food hasn’t changed. Why is this happening?

Cindy

To paraphrase Gabriel García Márquez, there are two types of cats in this world: Those that can poop, and those that cannot. Unfortunately for the cats involved, many move from the first group into the second as they age.

Cindy, the background and symptoms you describe are typical of chronic constipation, which most frequently affects older cats. These poor souls often struggle unsuccessfully to move their bowels in the litter box. They may vocalize during or after their attempts. They frequently strain so hard that they vomit. And then they sometimes enjoy success outside of the box. I don’t know why some cats seem to have better luck on the bed or on a nice carpet — some people might call it substrate preference, whereas others might call it Murphy’s Law.

A combination of factors create constipation in older cats. Decreased intestinal movement appears to be a prime cause. Normal movement of food through the intestines, and feces through the colon and rectum, depends on muscular action of the bowel structures. This action is controlled by the nervous system, and it decreases with age. This may be due to intrinsic issues with the muscles involved in the bowel, the deterioration of the nervous tissues, or both.

Chronic dehydration is another factor. Kidney disease, which is nearly ubiquitous in 18-year-old cats, leads to dehydration. The body tries to conserve water by drawing it out of the feces, which become firmer (sometimes this is obvious upon inspection) and harder to pass.

Finally, older cats are weaker and frailer than their younger counterparts, so their straining is less effective.

Constipation is a serious matter. As any person who’s experienced it knows, it’s very uncomfortable. It can suppress appetite and lead to weight loss. The protracted ineffective straining of affected cats can lead not only to vomiting but to complete exhaustion and collapse or even death.

Sadly, feline constipation usually is progressive. Fortunately, there are some steps that can be taken to prevent cats from ending up like Elvis.

There are several treatments for constipation. Fiber supplements help to add form and bulk to the feces, which in turn helps the intestinal muscles gain purchase and keep things moving. Feline-specific fiber supplements are available through pet stores and veterinarians. Some vets also recommend canned pumpkin (make sure it’s not spiced for pies) as a fiber supplement. Changing the diet to one that is high in fiber and moisture also may be of benefit. Keeping plenty of fresh water sources around the house will encourage your cat’s fluid consumption and may help with the dehydration.

Mild laxatives often help. The most commonly used ones are marketed as hairball remedies such as Laxatone and Petromalt. These products contain petroleum jelly, which lubricates the intestines and promotes defecation. They can be given daily as needed (I recommend the minimum effective amount and frequency).

Refractory constipation may respond to a prescription-only product called lactulose, a powerful laxative that often causes diarrhea in people, but many cats respond favorably to it. Another medication, cisapride, increases intestinal motility, but is usually used in only serious cases because of the potential for side effects and because it is difficult to obtain.

Some owners administer fluid injections to their cats, which helps reduce chronic dehydration that can contribute to constipation.

Enemas are often used for cats that have an urgent need to pass their bowels, but these are usually performed at veterinary offices. They aren’t an everyday home treatment, but highly motivated owners (who don’t mind cleaning up afterwards) sometimes administer enemas to their cats on a regular basis.

Chronic constipation is unfortunately common in older cats. However, for the majority of individuals, some combination of the treatments listed above brings long-term relief. Before embarking on a home-treatment regimen, talk to your vet to make sure the plan is appropriate and to confirm that concurrent medical problems are not contributing to the issue.